ABSTRACT
BACKGROUND: Exercise tests are an important tool in the investigation of myocardial ischemia. The ramp protocol has gained increasing importance in clinical practice because of the possibility of individualizing its exercise intensity. OBJECTIVE: To assess and compare the sensitivity, specificity, and accuracy of Bruce and ramp protocols for exercise testing in the diagnosis of myocardial ischemia considering myocardial perfusion scintigraphy as the reference standard. Secondary objectives included the assessment of hemodynamic profiles, functional capacity, and the incidence of arrhythmias in each of the protocols. METHODS: Participants underwent exercise testing using the ramp and Bruce protocols, and the tests' diagnostic power was assessed. For testing the difference between data provided by both protocols, we used a paired Student's t-test or Wilcoxon test, depending on the assumption of data normality. The level of significance adopted for all tests was 5%. RESULTS: The ramp protocol showed sensitivity, specificity, and accuracy values of 55.6%, 82.4%, and 76.7%, respectively, whereas the Bruce protocol had results of 77.8%, 64.7%, and 67.4%, respectively. The maximum heart rate and double product at peak exercise were significantly higher in the Bruce protocol (p = 0.043 and p = 0.040, respectively). No differences were observed between the incidence of arrhythmias in both protocols. CONCLUSION: The Bruce protocol presented higher sensitivity for detecting ischemia on the exercise test, while the ramp protocol presented higher specificity and accuracy.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Coronary Artery Disease/diagnosis , Myocardial Ischemia/diagnosis , Exercise Test , Myocardial Perfusion Imaging/methods , Exercise , Predictive Value of Tests , HemodynamicsABSTRACT
Cardiopulmonary exercise testing is widely used in the evaluation of patients with left ventricular dysfunction, and some of these patients have an implantable cardioverter-defibrillator (ICD). However, this test presents specific challenges because of the susceptibility to ventricular arrhythmias during maximal levels of exercise. Objective: To evaluate the safety of cardiopulmonary exercise testing in patients with ICD. Methods: The study included patients with ICD who underwent cardiopulmonary exercise testing between 2007 and 2015. The tests were completed once the electronic devices were programmed. The maximum allowed heart rate reached during exercise was 10 beats below the first therapy zone programmed. Results: The study included 69 patients with mean age 53.7 ± 10.8 years, including 68% men. Exercise time was 8.7±2.3 minutes, with peak oxygen consumption of 13.3 ± 4.3 ml.kg-1.min-1. Peak heart rate was 62.9 ± 13.4% of the maximum rate predicted, with all patients taking specific medication. Ventricular arrhythmia was observed in 29% of the patients, and paired ventricular extrasystoles, ventricular bigeminism or non-sustained ventricular tachycardia were observed in only 14.5% of the patients. There was no sustained ventricular arrhythmia resulting in ICD therapy or other complications, such as inappropriate therapies. The frequency of severe events was 0%, 95% CI (0 - 5.2%). Conclusion: In the sample of patients evaluated, the cardiopulmonary exercise testing was shown to be safe during its performance in a hospital setting, following the safety standards